//#define _CRT_SECURE_NO_WARNINGS 1
//#include <iostream>
//#include <string>
//#include <stdbool.h>
//using namespace std;
////int main()
////{
////	string a = "hello world";
////	string b = a;
////	if (a.c_str() == b.c_str())
////	{
////		cout << "true" << endl;
////	}
////	else cout << "false" << endl;
////	string c = b;
////	c = "";
////	if (a.c_str() == b.c_str())
////	{
////		cout << "true" << endl;
////	}
////	else cout << "false" << endl;
////	a = "";
////	if (a.c_str() == b.c_str())
////	{
////		cout << "true" << endl;
////	}
////	else cout << "false" << endl;
////	return 0;
////}
//
//
//
////int main(int argc, char* argv[])
////{
////	string strText = "How are you?";
////	string strSeparator = " ";
////	string strResult;
////	int size_pos = 0;
////	int size_prev_pos = 0;
////	//
////	while ((size_pos = strText.find_first_of(strSeparator, size_pos)) != string::npos)
////	{
////		strResult = strText.substr(size_prev_pos, size_pos - size_prev_pos);
////		cout << strResult << " ";
////		size_prev_pos = ++size_pos;
////	}
////	if (size_prev_pos != strText.size())
////	{
////		strResult = strText.substr(size_prev_pos, size_pos - size_prev_pos);
////		cout << strResult << " ";
////	}
////	cout << endl;
////	return 0;
////}
//
//
//bool isPalindrome(string s) {
//    int begin = 0;
//    int end = s.size() - 1;
//    while (begin < end)
//    {
//        while (!isalpha(s[begin]) && !isdigit(s[begin]) && begin < end)
//            begin++;
//        while (!isalpha(s[end]) && !isdigit(s[end]) && begin < end)
//            end--;
//
//        if (s[begin] >= 'A' && s[begin] <= 'Z')
//            s[begin] = tolower(s[begin]);
//        if (s[end] >= 'A' && s[end] <= 'Z')
//            s[end] = tolower(s[end]);
//
//        if (s[begin] != s[end])
//            return false;
//
//        if (begin < end)
//        {
//            ++begin;
//            --end;
//        }
//    }
//    return true;
//}
//
//int main()
//{
//    string s("ab2a");
//    bool ret = isPalindrome(s);
//    return 0;
//}